Question

comparati nr:a)$3^{38} si 2^{57}$ . b)$3^{87} si 9^{43}$

Answer 1

                
$a) \\ 3^{38} = 2^{(2*19)}=(3^{2})^{19} = 9^{19} \\ 2^{57}=2^{(3*19)}=(2^{3})^{19}=8^{19} \\ 9^{19}>8^{19} \\ => 3^{38}>2^{57} \\ \\ \\ b) \\ 3^{87} \\ 9^{43} = (3^{2})^{43}=3^{(2*43)}=3^{86} \\ 3^{87} >3^{86} \\ =>3^{87} >9^{43}$